﻿#include"Date.h"

bool Date::CheckDate()
{
	if (_month < 1 || _month > 12
		|| _day < 1 || _day > GetMonthDay(_year, _month))
	{
		return false;
	}
	else
	{
		return true;
	}
}

bool Date::operator<(const Date& d) const
{
	if (_year < d._year)
	{
		return true;
	}
	else if (_year == d._year)
	{
		if (_month < d._month)
		{
			return true;
		}
		else if (_month == d._month)
		{
			return _day < d._day;
		}
	}
	
	return false;
}
bool Date::operator<=(const Date& d) const
{
	return *this < d || *this == d;
}
bool Date::operator>(const Date& d) const
{
	return !(*this < d);
}
bool Date::operator>=(const Date& d) const
{
	return *this > d || *this == d;
}
bool Date::operator==(const Date& d) const
{
	return _year == d._year
		&& _month == d._month
		&& _day == d._day;
}
bool Date::operator!=(const Date& d) const
{
	return !(*this == d);
}

Date& Date::operator+=(int day)
{
	if (day < 0)
	{
		return *this -= day;
	}

	_day += day;
	while (_day > GetMonthDay(_year, _month))
	{
		_day -= GetMonthDay(_year, _month);
		_month += 1;
		if (_month > 12)
		{
			_month -= 12;
			_year += 1;
		}
	}
	return *this;
}
Date Date::operator+(int day) const
{
	Date tmp = *this;
	tmp += day;

	return tmp;
}
// d1 -= 天数
Date& Date::operator-=(int day)
{
	if (day < 0)
	{
		return *this += -day;
	}

	_day -= day;
	while (_day <= 0)
	{
		_month -= 1;
		if (_month == 0)
		{
			_month = 12;
			_year -= 1;
		}
		_day += GetMonthDay(_year, _month);
	}
	return *this;
}
Date Date::operator-(int day) const
{
	Date tmp = *this;
	tmp -= day;

	return tmp;
}
// d1 - d2
int Date::operator-(const Date& d) const
{
	Date max = *this;
	Date min = d;
	int flag = 1;
	if (max < min)
	{
		max = d;
		min = *this;
		flag = -1;
	}

	int n = 0;
	while (max != min)
	{
		min++;
		n++;
	}

	return n * flag;
}
// ++d1 -> d1.operator++()
Date& Date::operator++()
{
	*this += 1;
	return *this;
}
//d1++
Date& Date::operator++(int)
{
	Date tmp = *this;
	*this += 1;
	return tmp;
}

// --d1 -> d1.operator++()
Date& Date::operator--()
{
	*this -= 1;
	return *this;
}
//d1--
Date& Date::operator--(int)
{
	Date tmp = *this;
	*this -= 1;
	return tmp;
}

ostream& operator<<(ostream& out, const Date& d)
{
	out << d._year << "年" << d._month << "⽉" << d._day << "⽇" << endl;
	return out;
}

istream& operator>>(istream& in, Date& d)
{
	cout << "请依次输⼊年⽉⽇:>";
	in >> d._year >> d._month >> d._day;
	if (!d.CheckDate())
	{
		cout << "⽇期⾮法" << endl;
	}

	return in;
}